Transmissionless washing machine with modulated recirculation

ABSTRACT

A recirculation-type washing machine in which a high volume, low pressure centrifugal pump and a mechanically modulated nozzle replace the usual agitator, transmission gear case, associated superstructure, and drain pump in an otherwise conventional toploading, automatic washer. The nozzle is mechanically modulated to produce a spatially unsymmetrical field of turbulence which sweeps cyclically around within the wash basket to create the required rollover and mechanical agitation of the wash load. Within an optimum range of nozzle modulation frequency, nozzle area, and flow rate, a high level of soil removal performance is achieved with substantially no tangling.

United States Patent Hurwitz TRANSMISSIONLESS WASHING MACHINE WITHMODULATED RECIRCULATION [76] Inventor: Mathew Hurwitz, 63 Oakland Ave.,

Auburdale, Mass. 02166 [22] Filed: July 13, 1973 [211 Appl. No.: 379,120

[52] 11.8. CI. 68/184, 68/235 151 1 Int. (Il D061 17/04, D06f 23/04 [58]Field of Search 1. 68/184, 148, 23.5, 207; 134/176, 178

[56] References Cited UNITED STATES PATENTS 2,135,261 11/1938 Rosmait68/184 X 2,502,702 4/1950 Castner 68/207 X 2,767,569 10/1956 68/184 X3,368,573 2/1968 134/176 3,413,827 12/1968 Kochanek 68/184 X PrimaryExaminer-Billy J. Wilhite Assistant Examiner-Philip R. Coe Attorney,Agent, or FirmArnstein, Gluck, Weitzenfeld & Minow [57] ABSTRACT Arecirculation-type washing machine in which a high volume, low pressurecentrifugal pump and a mechanically modulated nozzle replace the usualagitator, transmission gear case, associated superstructure, and drainpump in an otherwise conventional top-loading, automatic washer. Thenozzle is mechanically modulated to produce a spatially unsymmetricalfield of turbulence which sweeps cyclically around within the washbasket to create the required rollover and mechanical agitation of thewash load. Within an optimum range of nozzle modulation frequency,nozzle area, and flow rate, a high level arson removal performance isachieved with substantially no tangling.

7 Claims, 5 Drawing Figures PATENIEB FEB 2 51975 SHEET 2 BF 3/llnvvrillinfill-35"?! M0 TOR TRANSMISSIONLESS WASHING MACHINE WITHMODULATED RECIRCULATION BACKGROUND OF THE INVENTION Top-loading,automatic washing machines which combine the convenience of washing,rinsing, and spin extraction in a single tub with the simplicity andeconomy of a recirculator to replace the standard agitator arepreviously known. However, domestic manufacturers have been reluctant tointroduce any of these prior designs to the market for a number ofreasons. They tangle most wash loads, they are not competitive in soilremoval performance, and, they depart so drastically in concept andconfiguration from the machines which the major domestic manufacturersare geared to build that the required investment to retool and to modifyassembly facilities cannot be reconciled with the anticipated return.

SUMMARY OF THE INVENTION The present invention provides a top-loading,automatic washing machine which is both capable of meeting theperformance expectations of the modern consumer and at the same time isable to satisfy the practical requirements of the manufacturer andretailer. In particular, the present invention provides the consumerwith a completely automatic, low-cost top-loading washer which deliverssubstantially the same soil removal performance as an agitator-typewasher and which is non-tangling, capable of handling family size loads,and gentle to delicate fabrics. At the same time, the present inventionprovides the retailer and the manufacturer of conventional washers witha new washer concept which is simple, cost effective, reliable, andcapable of being sold and serviced by existing personnel throughexisting facilities. The present invention is compatible with a majorityof present-day, top-loading washing machines designs. Thus, it can beincorporated into these machines with minimal tooling expense and withlittle or no change to existing engineering and assembly methods.

Accordingly, it is an object of the present invention to provide anotherwise conventional top-loading automatic washing machine in whichthe standard agitator, gear case, associated superstructure, and drainpump are replaced by a recirculating loop comprised of a pump and amechanically modulated nozzle.

Another object of this invention is to provide a fully automatic, toploading, recirculation-type washer capable of achieving acceptable soilremoval with minimum tangling when operated with family sized loads.

Still another object of this invention is provision of a washing machinewhich is gentle to delicate fabrics.

A further object of this invention is the provision of a pump/nozzlearrangement which is compatible with present top-loading washing machinedesigns so that it may be embraced by manufacturers of conventionalwashers with a minimum of retooling or reconfiguration of assemblylines.

Otner and further objects and advantages of the present invention willbecome apparent from the following description when considered inconnection with the accompanying drawings and the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a washingmachine in accordance with a preferred embodiment of my invention, withcertain parts cut away and in cross-section to illustrate structuraldetails.

FIG. 2 is a functional diagram of the machine illustrated in FIG. 1showing typical interrelationship of the component parts of the machine.

FIG. 3 is a vertical cross-sectional view, partly in elevation,illustrating the nozzle assembly and a typical mechanism formechanically modulating the nozzle.

FIG. 4 is a cross-sectional view taken substantially on line 4-4 of FIG.3 and,

FIG. 5 is a diagrammatic cross-sectional view taken substantially online 5-5 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 illustrate a moreor less conventional top-loading automatic washing machine of well-knownmanufacture incorporating the features of my invention presently to bedescribed.

The basic washing machine and the apparatus of my invention is housedwithin a cabinet assembly 10 having a top 11 provided with a hinged lid12. A base plate 13 is supported by a plurality of vibration-isolatorsuspension rods 14 depending from the top of the cabinet 10. Supportedin a well known manner are the conventional tub assembly 16, washbasket17 and motor 18. In place of the usual gear case, drain pump, associatedsuperstructure, and agitator, there are located beneath the base plate13 in depending relation, a pump 19, a lint filter 21 and a one wayclutch 23, typically a spragclutch. Connected via duct 28a to the outletof pump 19 is a two-way flapper valve 24 actuated by an electricalsolenoid 26 through linkage 27. The function of the flapper valve 24will be hereinafter described. Connected to the main discharge port 24aof valve 24 is a nozzle supply hose 28 which is connected to the inletduct 29 of a nozzle assembly 31. Connected to the secondary dischargeport 24b of valve 24 is a tee connector 33 havingg two branches. Onebranch is connected to an inlet bypass hose 32 and the other branch isconnected via hose 94 to the outlet of a lint filter 21.

The nozzle assembly 31 includes a generally cylindrical nozzle tube 34surmounted by a closure cap 36 and having an inlet duct 29, all shapedsubstantially as illustrated in FIG. 3. Preferably, the nozzle tube andinlet duct are integrally molded from a suitable tough material such aspolycarbonate plastic. The lower end of the nozzle tube 34 opens to amouth 38 which, preferably, has a reduced diameter in relation to thatof the main body of the nozzle tube 34. An annular flanged ring 39 issuitably attached to the inner wall of the body portion 34 at a pointslightly above the juncture of the duct 29 with the nozzle tube 34.Suitably bonded to a shoulder 41 on the ring 39 is a flexible diaphragm42 which may be formed of thin stainless steel or of a suitablethickness of elastomeric material such as urethane rubber (Diisocyanatepolyester). The diaphragm 42 is provided with a central aperture throughwhich passes a nozzle support tube 43. This support tube 43 replaces theconventional washing machine agitator drive shaft and is mounted withinthe conventional basket drive tube 44 journaled within an upper bearing46 and corresponding lower bearing, not shown. The support tube 43 isfree to rotate relative to the basket drive tube 44 but is restricted bythe bearings against axial movement. A conventional seal 47 interposedbetween the nozzle support tube 43 and the basket drive tub 44 preventsthe entrance of water into the space between these two parts.Preferably, the support tube 43 is provided with annular grooves toreceive snap rings 48 and 49. A sleeve 51 is circumposed about thesupport tube 43 and is retained between the snap ring 49 and theflexible diaphragm 42. A gasket 52 is disposed adjacent the diaphragm 42and is surmounted by a retainer sleeve 53, both the gasket 52 and sleeve53 being confined by the snap ring 48. By the means above described, thenozzle assembly 31 is secured to the support tube 43 and is restrainedagainst axial movement but is free to rock or tilt relative to thesupport tube 43 by reason of the flexibility of diaphragm 42.

As noted above, the nozzle support tube 43 is disposed within the basketdrive tube 44 which in turn, is fixed, in a conventional manner, to thebasket center post 55 by a drive block 56, a spanner nut 57 and a seal58. The basket drive tube 44 is rotatably supported within the basketsupport tube 54 by an upper bearing 61 and a corresponding lowerbearing, not shown. Seals 62 and 63 located adjacent to the upper andlower ends of the bearing 61 protect the bearing from water and preventleakage of water through the space between the basket drive tube 44 andthe basket support tube 54.

Disposed within the nozzle tube 43 is a drive shaft 64, the lower end ofwhich extends below the clutch 23 and has fixed thereon a pulley 66. Theshaft of motor 18 has fixed thereon a pulley 67 and a narrow gage belt68 affords a driving connection between pulleys 67 and 66. The diameterof the pulley 67 is much smaller than that of pulley 66 to afford aspeed reduction ratio of the order of l2 to 1.

Referring FIG. 3, the upper end portion of the nozzle drive shaft 64extends above the upper end of the nozzle support tube 43 and has fixedthereon a roller crank 69. This crank includes a depending skirt portion71 in which is received a sleeve bearing 72 to provide radial supportand free rotation for the roller crank. The roller crank 69 is providedwith a bifurcated lateral extension 73 which supports a roller 74, theroller being suitably journaled for free rotation. A cap member 36 ispress-fitted over the upper opening of the nozzle tube 34 to enclose theroller mechanism.

The roller 74 is arranged to engage the inner surface 34a close to theupper opening of the nozzle tube 34 to the extent that it tilts thenozzle tube 34 so that its axis is not coincident with the axis of thedriveshaft 64. In other words, the axis of the nozzle tube 34 isinclined from the axis of the driveshaft 64 by a small angle 6, asindicated in FIG. 3. Accordingly, there is created at the mouth 38between the nozzle tube 34 and the basket centerpost 55 acrescent-shaped orifice 38a (FIG. having a maximum width at a point 180opposite the point of contact between the roller 74 and the innersurface 34a of the upper opening of the nozzle tube 34. It will be seenthat when the driveshaft 64 is rotated, the roller crank 69 is revolvedcausing the roller 74 to effect a nutational motion in the nozzleassembly 31. This causes the crescent shaped orifice 38a to orbit orprecess about the tub center post 55.

It will now be apparent that if a flow of water is pumped into the duct29, as will hereinafter be described, the flow of water being dischargedfrom the orbiting crescent shaped orifice 38a will establish a field ofturbulence affecting only a portion of the basket at any instant oftime. Clearly, as the roller crank 69 is rotated, this field ofturbulence must precess cyclically about the basket, such that in asingle revolution of the roller crank 69, the nozzle flow will bedirected in turn to all sectors of the basket. Accordingly, although theflow is steady in time, it is unsteady or cyclical in space within thebasket. This flow and the means for creating the same are the heart ofthe present invention.

Referring to FIGS. 1 and 2, the motor 18 carries a pulley 78 whichthrough belt 79 drives a pump pulley 81 and basket drive pulley 82. Themotor 18 is reversible. During the wash, rinse, and drain cycles themotor 18 operates in a forward direction driving the pump 19 in thedirection for which it is designed to deliver maximum efficiency. Whilethe motor 18 runs in this direction the basket drive pulley 82 functionsmerely as an idler by virtue of the one-way clutch 23 which permits thepulley 82 to run freely relative to the basket drive tube 44. Duringspin-extraction and spray-rinse cycles the motor 18 operates in areverse direction. In this mode the pump 19 is operating counter to itsmost efficient direction of rotation. However, its pumping capacity isadequate for pumping the small flows involved during these cycles. Withthe motor 18 operating in a reverse direction the basket drive pulley 82rotates in the proper direction to engage the one-way clutch 23 andthus, the basket drive tube 44 receives power from the motor 18 and thebasket 17 is caused to spin.

Although not essential, a second one-way clutch, not shown, may beutilized to couple the nozzle drive pulley 66 with the nozzle driveshaft 64 so as to permit a driving connection only when the motor 18 isrunning in the forward direction while free-wheeling when the motor isrunning in the reverse direction. This optional expedient affords ameans of prolonging the life of the nozzle modulating mechanism, sincemechanical movement of the nozzle is not required during the spin andspray-rinse cycles.

Referring to FIGS. 1 and 2, the plumbing circuit beginning with the tubdrain aperture 22 includes a pump inlet tee fitting 20 which surmountsthe pump 19. The pump includes an impeller 87 driven by shaft 88 onwhich is keyed pulley 81 driven by belt 79. A solenoidactuated two-wayflapper valve 24 is connected to the outlet of pump 19 by a duct 28a andthis valve operates to direct the flow of water from the pump, either tothe nozzle assembly 31 by way of hose 28 and duct 29 or to the teeconnector 33. The tee connector 33 is connected at one branch to abypass conduit 32 which connects to the pump inlet tee 20. The otherbranch of tee connector 33 connects to the outlet of filter 21 by way ofthe conduit 94. The filter 21 contains a lint screen 21a which isdesigned in the conventional manner to capture sand, bits of thread andthe like. A conduit 84 connects the filter inlet to the outlet of checkvalve 93. The check valve 93 contains two flappers. A first flapper 93aadmits water from the side of the tub 16 but prevents water from passingback thereto. A second flapper 93b allows water to pass to drain 97 burprevents air or water from re-entering. A solenoid 99 actuates waterinlet valve 102 which is connected to the inlet supply 101 with theoutlet of the valve being connected to a basket fill hose 103.

As may be seen by reference to FIG. 2, valves 24 and 102 are activelycontrolled by electrical solenoids while the flapper-type check valve 93is passively controlled by suctions or pressures within the system. Whenthe solenoid 26 which controls valve 24 deenergized, the

valve is normally open to the nozzle supply conduit 28 and is at thesame time closed off the tee 33. When the solenoid 99 controlling valve102 is deenergized, that valve is closed.

OPERATION To operate my washing machine, the user loads the laundry,adds detergent in the usual manner and actuates an automatic cyclecontroller of a conventional type to initiate the following sequence ofoperations. STEP 1. FILL The solenoid 99 is energized to open inletvalve 102 allowing water from the inlet supply 101 to fill the tub 16 toa level which is predetermined by a fill timer or by one of the commontypes of washing machine waterlevel switches. When the desired level isreached, solenoid 99 is deenergized to close the inlet valve 102.

STEP 2. WASH Both of the valve solenoids 26 and 99 are deengerized sothat valve 102 is closed and valve 24 is opento nozzle inlet conduit 28and closed to the tee connector 33. The motor 18 is energized to run ina forward direction and a main flow of water-enters the pump inlet viathe tub drain aperture 22. Pump suction causes the inlet flapper 93a ofvalve 93 to open so that a secondary flow of water from the tub 16 isdrawn via valve 93 through the lint filter 21. In this mode of operationthe flapper 93a is open and flapper 93b is held closed by pump suction.This filtered secondary flow joins the main flow at the pump filterinlet tee 20. The full output flow of the pump 19 is directed via thetwo way flapper valve 24 into the conduit 28 whence the flow passes tothe nozzle inlet duct 29 and from there into the space between thenozzle tube 34 and basket centerpost 55. The flow then discharges intothe basket through the crescent shaped orifice 38a. While this isoccuring the roller crank 69 is being rotated by the motor 18. Thisforces the roller 74 to rotate against the inner surface 34a of theupper end of the nozzle tube 34 which causes the entire nozzle tonutate. The nutating nozzle mouth 38 forms a rotating crescent-shapedorfice 38a with the basket centerpost 55. Water is discharged from thisorifice with great force into that sector of the basket 17 faced by thecrescent-shaped orifice 380 at any given instant. Because the orificeorbits the basket centerpost cyclically, all sectors of the basket 17,in turn, receive the full force of the discharge flow for eachrevolution of the crescent-shaped orifice 38a. This continually orbitingorifice produces within the basket a cyclic flow which is bothunsymmetrical and unsteady in space but which is steady in time. Thus,articles of laundry within the various sectors of the basket arealternately subjected to bursts of intense flow followed by intervals ofrelative quiescence. The result is an organized and repetitiousroll-over of the entire load, each article in turn receiving briefbursts of intense flow each time it passes through the discharge regionof the moving orifice. This action produces the required flexing oflaundry articles to provide the necessary mechanical influence for goodsoil removal. The circulation or roll-over of the load is self-startingand persistant, each article of laundry being moved unsteadily in aseries of small jerky motions rather than in steady, continuous motions.The unsteady motion prevents stagnation of the load and minimizestangling by maintaining an organized distribution of the wash load.

STEP 3. DRAIN AND BACKFLUSH FILTER Motor 18 is momentarily deenergizedand during the ensuing stoppage of flow, the solenoid 26 controllingvalve 24 is energized. This moves the flapper 240 within the valve toblock the outlet 24a to conduit 28 and to open the outlet 24b leading toconnector tee 33. Motor 18 is again energized to run in a forwarddirection and the flow is now directed from the tub drain aperture 22,through the pump 19, to the connector tee 33 where part of the flowreturns to the pump inlet via the bypass conduit 32 and the balance ofthe flow passes via the conduit 94 to the filter outlet. This flowbackflushes the lint screen 21a and passes to the side check valve 93wherein the pressure closes flapper 93a and opens 93b to permit thewater to exit the machine via the drain conduit 97. This operationcontinues for a timed interval of sufficient duration to completelyempty the tub of water and then the motor 18 and valve solenoid 26 areautomatically switched off. STEP 4. SPIN Solenoid 26 is again energizedas during the drain function described in Step 3 and the motor 18 isenergized to run in a reverse direction. The clutch 23 thereby engagesto transmit power from the basket drive pulley 82 to the basket drivetube 44 to spin the basket 17. Water remaining in the load is extractedby centrifugal force and is discharged to the drain via the same circuitas described in STEP 3 above. STEP 5. SPRAY RINSE During the spin cycleand after a predetermined time has elapsed to extract substantially allof the centrifugable water from the laundry load, solenoid 99 isenergized for a short interval to open valve 102 allowing a spray offresh water to pass through conduit 103 and impinge on the spinninglaundry load. Solenoid 99 is then deenergized to cut off the spray foran interval of time sufficient for most of the water just introduced tobe extracted by centrifugal force. Preferably, this spray cycle isrepeated several times. After the final spray, the spin cycle continuesfor a predetermined time of sufficient duration to extract substantiallyall of the centrifugable water from the load. Thereafter, the motor 18and solenoid 26 are deenergized. The basket 17 comes to rest and valve24 returns to its normal state wherein it is open to conduit 28 leadingto the nozzle 31. STEP 6. FILL The tub 16 is filled in the same manneras described in STEP 1. STEP 7. RINSE The solenoids 26 and 99 aredeenergized and the motor 18 is energized to run in a forward direction.The ensuing operation is identical to that occurring during the washfunction. STEP 8. DRAIN The components are actuated to repeat the cycleas described above in STEP 3. STEP 9. SPIN The spin funtion as describedabove in STEP 4 is repeated. STEP [0. SPRAY RINSE The spray rinsefunction as described above in STEP 5 is repeated. STEP 11. FINAL SPINAND SI-IUT OFF After the final spray, the spin cycle continues for apredetermined time of sufficient duration to centrifuge as much aspossible of the remaining water from the load. Thereafter, the motor 18and solenoid 26 are deenergized, the basket 17 comes to rest and thelaundry cycle ends.

DESIGN PARAMETERS FOR OPTIMUM PERFORMANCE Experimental evidencedemonstrates that an optimum nutational frequency exists wherein soilremoval is maximized and tangling is minimized.

When the nozzle modulation frequency is zero, the wash load circulatessluggishly or stagnates completely. Certain articles reside for longperiods near the nozzle orifice and become relatively clean while soilremoval in articles further removed from the orifice is very poor. Thearticles near the orifice frequently twist and tangle severly in thismode of operation.

When the nozzle modulation frequency is increased, a transition in thebehavior of the wash load occurs at a frequency generally in the rangebetween 20 and 50 cycles per minute; the wash load spontaneously beginsto circulate or roll within the basket in an organized and continuouslyrepetitive manner. However, tangling is quite severe at this incipentrollover point generally soil removal is poor also.

As nozzle modulation frequency is increased further to the range between50 to 170 cycles per minute tangling decreases and soil removal improvesenormously becoming controlled by hydraulic power at the nozzle orifice(as determined by the product of the volumetric flow rate times thenozzle orifice pressure drop.). Within that range it has been found thata nutational frequency between 125-140 cycles per minute produces goodsoil removal with negligible tangling.

If the nutational frequency is raised above this optimum, tanglingdecreases further but soil removal falls off somewhat (with nozzle powerheld constant). Thus any atempt to operate at nozzle modulationfrequencies above the optimum requires greater nozzle power to maintainsatisfactory soil removal.

in particular, within a common gallon washing machine basket having abasket centerpost 2.50 inches in diameter, excellent results may be hadwith a nozzle having a mouth diameter of 2.65 inches. This produces anozzle orifice area of 0.6 square inches. Operating this nozzle orificeat a flow rate of 60 GPM requires a nozzle power ofjust under one-fourthHP. With a pump whose efficiency is 60 percent and with plumbing lossesdissipating percent of the available hydraulic power, this translates toone-half HP required to power the pump. With this flow and with a nozzlemodulation frequency of 134 cycles per minute, soil removal using theindustry standard 5 pound mixed cotton load is within 90 percent of thatwhich can be achieved by a standard agitator mechanism operating in thesame washing machine with the same load, detergent concentration, watertemperature, and wash time. This preferred configuration is capable ofhandling standard mixed cotton loads up to 6 or 7 pounds dry weight withnegligible tangling.

Various changes coming with in the spirt of my invention may suggestthemselves to those skilled in the art; hence, I do not wish to belimited to the specific embodiments shown and described or usesmentioned, but intend the same to be merely exemplary, the scope of myinvnetion being limited only by the appended claims.

I claim:

1. In a top-loading automatic clothes washing machine, in combination, atub adapted to contain a body of liquid, a cylindrical basket withinsaid tub, mechanically modulated nozzle having an inlet duct and anoutlet orifice, said outlet orifice being disposed below the surface ofthe body of liquid when the same is contained in the tub, arecirculating pump connected to said tub and said inlet duct, means fordriving said pump, means for cyclically modulating the geometry of saidorifice so as to direct into said body of liquid a flow of liquid whichis spatially unsteady thereby creating in the body of liquid within saidbasket an unsymmetrical field of turbulence which sweeps cyclicallyaround the interior of the basket in synchronism with the frequency ofmodulation of the nozzle.

2. In a top-loading automatic washing machine, in combination, a tubadapted to contain a body of liquid, a cylindrical basket within saidtub, a vertical post disposed centrally of said basket, a nozzle havingan upper inlet and a lower outlet and circumposed about said post withthe internal diameter of said nozzle being greater than the externaldiameter of the post, means for supporting said nozzle on said post fornutational movement in relation to said post, means for effectingnutational movement of said nozzle whereby the outlet is disposedeccentric to said post to provide a nonsymmetrical discharge orificewhich precesses about the axis of said post, a recirculating pump,conduits connecting said pump with said inlet and said tub, drive meansfor driving said pump to continuously pump liquid from the tub to saidinlet for discharge through said orifice to create in the liquid withinthe basket a field of turbulence which is spatially unsymmetrical andwhich sweeps cyclically around the basket.

3. The invention as defined in claim 2 in which the means for effectingnutational movement of the nozzle comprises a drive shaft rotatablysupported within the post and a roller cam eccentrically fixed on saidshaft and engageable with the upper end of said nozzle.

4. The invention as defined in claim 2 in which the means for supportingthe nozzle on the post comprises a flexible diaphragm connectablyjoining said post to the inner surface of said nozzle.

5. The invention as defined in claim 2 in which the orifice is generallycrescent shaped.

6. The invention as defined in claim 2 wherein for each cycle of saidorifice the field of turbulence is directed cyclically to each sector ofthe basket.

7. In a top-loading automatic clothes washing machine, in combination, atub adapted to contain a body of liquid, a cylindrical basket withinsaid tub, a mechanically modulated non-rotating nozzle supported fornutational movement about a vertical axis and having an inlet duct andan outlet orifice, a recirculating pump connected to said tub and saidinlet duct, means for driving said pump, means for cyclically modulatingthe geometry of said orifice so as to direct into said body of liquid aflow of liquid which is spatially unsteady thereby creating in the bodyof liquid within said basket an unsymmetrical field of turbulence whichsweeps cyclically around the interior of the baskets in synchronism withthe frequency of modulation of the nozzle.

1. In a top-loading automatic clothes washing machine, in combination, a tub adapted to contain a body of liquid, a cylindrical basket within said tub, mechanically modulated nozzle having an inlet duct and an outlet orifice, said outlet orifice being disposed below the surface of the body of liquid when the same is contained in the tub, a recirculating pump connected to said tub and said inlet duct, means for driving said pump, means for cyclically modulating the geometry of said orifice so as to direct into said body of liquid a flow of liquid which is spatially unsteady thereby creating in the body of liquid within said basket an unsymmetrical field of turbulence which sweeps cyclically around the interior of the basket in synchronism with the frequency of modulation of the nozzle.
 2. In a top-loading automatic washing machine, in combination, a tub adapted to contain a body of liquid, a cylindrical basket within said tub, a vertical post disposed centrally of said basket, a nozzle having an upper inlet and a lower outlet and circumposed about said post with the internal diameter of said nozzle being greater than the external diameter of the post, means for supporting said nozzle on said post for nutational movement in relation to said post, means for effecting nutational movement of said nozzle whereby the outlet is disposed eccentric to said post to provide a non-symmetrical discharge orifice which precesses about the axis of said post, a recirculating pump, conduits connecting said pump with said inlet and said tub, drive means for driving said pump to continuously pump liquid from the tub to said inlet for discharge through said orifice to create in the liquid within the basket a field of turbulence which is spatially unsymmetrical and which sweeps cyclically around the basket.
 3. The invention as defined in claim 2 in which the means for effecting nutational movement of the nozzle comprises a drive shaft rotatably supported within the post and a roller cam eccentrically fixed on said shaft and engageable with the upper end of said nozzle.
 4. The invention as defined in claim 2 in which the means for supporting the nozzle on the post comprises a flexible diaphragm connectably joining said post to the inner surface of said nozzle.
 5. The invention as defined in claim 2 in which the orifice is generally crescent shaped.
 6. The invention as defined in claim 2 wherein for each cycle of said orifice the field of turbulence is directed cyclically to each sector of the basket.
 7. In a top-loading automatic clothes washing machine, in combination, a tub adapted to contain a body of liquid, a cylindrical basket within said tub, a mechanically modulated non-rotating nozzle supported for nutational movement about a vertical axis and having an inlet duct and an outlet orifice, a recirculatIng pump connected to said tub and said inlet duct, means for driving said pump, means for cyclically modulating the geometry of said orifice so as to direct into said body of liquid a flow of liquid which is spatially unsteady thereby creating in the body of liquid within said basket an unsymmetrical field of turbulence which sweeps cyclically around the interior of the baskets in synchronism with the frequency of modulation of the nozzle. 